Arturo Vidal scored the lone goal last night in front of 24,687 fans at Commonwealth Stadium to give Chile a 1-0 victory over Portugal in their second-round game at the FIFA Under-20 World Cup.

Vidal then picked up two yellow cards - the second for wasting time late in the game - which suspends the star midfielder for Chile's quarterfinal against Nigeria Sunday in Montreal.

"It's a big loss for us," said Chilean head coach Jose Sulantay. "But you have to have players that you can use as replacements, so it's not a big deal if you lose one or two players.

"It's too bad, but we have to continue playing the same way."

Vidal, Chile's midfield general, picked up his first yellow card of the game 15 minutes into the second half for a late challenge. Then he was issued a second yellow card, literally seconds from the end of the game, for taking his time with a free kick.

The second caution meant an automatic expulsion which comes with a one-game suspension. Vidal did not stop to talk to reporters after the game.

"But we have always said if we're short a player we have others that can come off the bench and play just as well or even better. So for that reason we're still pretty calm about the situation."

Making matters worse is that star striker Alexis Sanchez had to be substituted in the 76th minute with a shoulder injury. He could also be out for the next game.

"Sanchez came into the game with the injury to his shoulder, and also with a sore back," Sulantay said.

"We hope from here until Sunday he'll be able to play. If not, we're going to have to wait until the next game if we get that far. But Alexis Sanchez is a big percentage of the attacking force of our team."

Last night Sanchez was kept in check by the Portuguese defence, but Vidal was able to find some space at the end of the first half to score the winner.

Off a free kick Hans Martinez flicked a ball towards Nicolas Media who headed it down to Vidal at the far post.

"I'm glad I was able to get a head to that ball which led to the goal, I'm very happy," Martinez said.

"I know that (Maurico) Isla who took the free kick likes to put them in a certain spot and I was able to get there first."

Chile dominated play in the first half as Portugal sat back and defended.

"In my worst dreams I never thought we would play a game like that," said Portugal's head coach Jose Couceiro through an interpreter.

"We couldn't get possession of the ball. In the first half we played very badly. And things got worse when they scored a goal at the end of the half."

Chile had 14 shots at the net in the first half - seven of them on target.

"We weren't expecting to play such a bad game," Couceiro said.

Towards the end Portugal had two players sent off which essentially killed off any chance of a comeback.